Liquid fuel compositions containing as anti-corrosion agent an alkyl monoalkanol amino compound



United States Patent Chico 3,372,659 Patented Mar. 5, 1968 3,372,009 LIQUID FUEL C(BMPGSITHGNS CONTAINING AS ANTI-CORROSION AGENT AN ALKYL MQNO- ALKANQL AMINO COMPOUND Hans F. Waldmann, Glassboro, N.J., assignor to Mobil Oil (Importation, a corporation of New York No Drawing. Filed June 18, 1964, Ser. N 376,263 9 Claims. (Cl. 44-72) The present invention is directed to improved liquid hydrocarbon fuel compositions. More particularly, it is concerned with non-lubricating liquid hydrocarbon fuel fractions possessing improved vapor phase anti-corrosion characteristics.

The corrosion of the metal surfaces of storage and transportation facilities used for liquid hydrocarbon fuels is a well known problem. During storage and handling such fuels often pick up considerable amounts of water. For example, storage vessels for liquid fuels generally breathe with a resulting accumulation of water in the vessel. When the fuel is rernOVed for transportation, suificient water may be carried along to cause the corrosion or rusting of the metal surfaces of tankers, pipelines, and the like. The presence of corrosion products in liquid fuels adversely affects the characteristics of these fuels by causing the clogging of various equipment parts such as nozzles, screens, filters and the like.

A significant portion of such corrosion often occurs at metal surfaces which are above the level of the liquid fuel or otherwise not at all times in direct contact with the fuel. These metal surfaces wholly or partially enclose the vapor spaces above the level of the liquid fuel. The provision for a means of preventing or inhibiting this vapor phase-corrosion would be highly desirable.

It is therefore the principal object of the present invention to provide a means for improving the vapor phase anti-corrosion characteristics of liquid hydrocarbon fuels. A further object is to provide liquid hydrocarbon fuel compositions exhibiting improved vapor phase corrosion resistance and other desirable properties. Other objects of the invention as well as some advantages thereof will become apparent hereinafter.

The foregoing and other objects are achieved by incorporating into the fuels certain alkyl amino monoalkanols possessing the general formula:

where Rrepresents an alkyl group; R represents an alkyl group the same or different from R, or a hydrogen atom; R and R are selected so that sum of the groups represented by R+R' does not exceed carbon atoms; X is an alkylene group having from 2 to about 4 carbonatoms; and n is l or 2.

The alkyl groups present in these amine compounds may be either straight or branched-chain; primary, secondary or tertiary alkyls so long as the combined total of carbon atoms does not exceed ten. Similarly, the alkylene groups represented by X may be straight or branched-chain and can be derived from either primary, secondary or tertiary alkyls.

It will be seen from the above general formula that the compounds encompassed thereby may be characterized as monoalkyl or dialkyl amino mono-alkanols or allroxy mono-alkanols. Some examples of such compounds include: monomethyl amino ethanol, dimethyl amino ethanol, monoethyl amino ethanol, monoethyl amino ethoxy ethanol, diethyl amino ethanol, diethyl amino ethoxy ethanol, diisopropyl amino ethanol, dib-utyl amino ethanol, dibutyl amino ethoxy ethanol, n-butyl amino ethanol, dimethylamino-Z-propanol, diisopropyl amino Z-propanol, n-butyl amino Z-propanol, isobutyl amino 2-propanol, dirnethyl amino Z-butanol, dirnethyl amino l-butanol, etc.

The alkyl amino-mono-alkanols described herein, in general, may be advantageously employed in liquid hydrocarbon fuel which are subject to conditions which promote vapor phase corrosion. Although the fuel compositions of the invention are particularly effective in inhibiting water-induced vapor phase corrosion, they are effective against the corrosion of metal surfaces enclosing the vapor spaces in systems or apparatus where no water is present.

The present invention is particularly directed to improving the vapor phase corrosion resistance of liquid hydrocarbon fuels which contain water as an impurity or otherwise and which are subjected to conditions which promote vapor phase corrosion of metal surfaces. The amount of water which tends to cause, promote or induce the vapor phase corrosion will depend on such factors as the nature of the hydrocarbon fuel, the type of metal surface, temperature conditions, duration of exposure etc. In some instances as little as 0.01% by weight may be enough for corrosion.

This invention is therefore especially advantageous in improving the vapor phase anti-corrosion qualities of liquid hydrocarbon fuels which prior to use are subjected to periods of storage under conditions which promote vapor phase corrosion particularly of the Water-induced type. It should be noted that the problem of inhibiting vapor phase corrosion during periods of storage, often of long duration, is distinctly different from modifying fuels to improve their combustion or burning characteristics during use.

The hydrocarbon fuels improved in accordance with the present invention are normally liquid hydrocarbon fuels heavier than gasoline such as, for example, those liquid hydrocarbon fuels having an initial boiling point of the order of about 400 F. This includes kerosines, diesel fuels, jet fuels of these boiling ranges, light distillates such as furnace oil, light oils both straight run and catalytically cracked, as well as heavy oils and residual fuels. Especially contemplated herein are the distillate fuel oils having initial boiling points of the order of about 400 P. such as No. 1 and No. 2 fuel oils used for domestic heating and as diesel oils. Further and more specific descriptions of some examples of these liquid hydrocarbon fuels boiling above gasoline are given in the ASTM specifications relating thereto.

The ability of the aforedescribed alkyl amino monoalkanols as vapor phase corrosion inhibitors in the liquid hydrocarbon fuels will be seen from the results obtained in the following Vapor Phase Anti-Rust Test.

Vapor phase anti-rust test According to the test procedure, a 16 ounce tallform widemouth glass jar is half filled with a N0. 2 fuel oil containing 15 weight percent of water. A sandblasted and solvent-cleaned steel test panel is attached to the inside of a tin lid with a magnet parallel to the level of the fuel and the lid then screwed loosely onto the glass jar to allow some breathing. The jar is then immersed overnight up to the liquid level in a water bath maintained at 180 F. and during the day removed and stored for 8 hours. The vapor phase anti-rust capability of the fuel oil is determined by measuring the percent of the test panel surface which is rusted after various periods. The smaller percent of rusting the more effective the inhibitor.

The results obtained using a No. 2 fuel oil containing 80% of a 350650 F. distillate, 15% of a 600 F. end point gas oil and of a 300-400 F. naphtha are reported in Table 1. The test results obtained using a different No. 2 fuel oil containing 50% of a 350650 F. distillate, 25% of a 600 F. end point gas oil and 25% of a light Coker oil which has been treated in a hydrodesulfurizer are reported in Table 2.

The isopropylarninoethanol employed in the following tests is, unless otherwise indicated, a commercially availa- I ble product comprising a mixture of alkyl alkanol amines containing about 60% of isopropylaminoethanol.

0.1 to about 1.0 wt. percent. In some instances, larger amounts may be employed depending primarily on economic considerations.

If desired, the liquid hydrocarbon fuels of the invention may also contain other additives designed to impart other improved characteristics to the fuels. Thus, for example, foam inhibitors, burning and ignition improvers, etc., may be used.

It will, of course, be appreciated that many modifications and variations may be practiced without departing from the scope and spirit of the present invention.

Having thus described the invention what I desire to secure and claim by Letters Patent is:

1. A liquid hydrodesulfurized hydrocarbon fuel composition normally tending to promote vapor phase corrosion, containing a liquid hydrodesulfurized hydrocarbon fuel heavier than gasoline and an effective amount of an alkyl amino mono-alkanol compound of the formula:

where R represents an alkyl group having from 1 to about carbon atoms; X is an alkylene group having from TABLE 1.VAPOR PHASE ANTI-RUST TEST 1N FUEL OIL H2O Percent of Panel Surface Iusted After Cycling to 180 F. or-

Test N0 Fuel Inhibitor (0.2%)

6 days 9 days 12 days 35 days 65 days 40 50 100 Isopropylarninoethanol 0 0 0 2 4 Diethylaminoethanol 15 15 15 40 Ethylarninoethanol. 0 O 0 3 Diisopropylaminoethanol. 45 5O 75 90 Dimethylaminoethanol 1 1 2 3 3 lviethylamincethanol 0 0 0 5 65 ButylaminoethanoL. 0 0 0 l 6 Isopropylaminoetha 3 4 7 1O 10 Diethylarninoethoxyethanol. 10 10 10 15 18 Dimethylamino-2-propanol 25 25 30 50 65 1 No. 2 fuel oil containing 80% ot a 350-650 F. distillate, 15% of a 600 F. end point gas oil and 5% of a 300-400 F. naphtha.

2 Pure compound.

TABLE 2.VAPOR PHASE ANTLRUST TEST IN FUEL OIL 15% H2O Percent of Panel Surface Rusted After Cycling to 180 F.

for

Test No Fuel Inhibitor (0.2%)

6 days 9 days 12 days days 65 days 100 IsopropylaminoethanoL- 0 0 0 2 4 Diethylaminoethanol 20 20 20 30 Ethylaminoethanol 0 0 0 3 DiisopropylaminoethanoL 20 30 35 40 50 DimethylaminoethanoL 6 6 6 6 6 Methylaminoethanol. 0 0 0 2 5 Butylaminoethanol 0 0 0 3 20 Isopropylaminoethanol s 0 0 O 0 1 Diethylaminoethoxyethanol. 25 50 50 6O 75 DimethylaminoZ-propanol 1O 15 15 25 25 1 No. 2 fuel oil containing 50% of a 350-650 F. distillate, 25% of a 600 F.

treated in a hydrodesulfurizer.

1 Pure compound.

It is believed that the foregoing test results demonstrate the surprising ability of the instant alkyl amino mono-alkanol compounds to impart effective and longlasting corrosion resistance.

The alkyl amino mono-alkanol compounds of this invention may be employed in the form of relatively pure individual compounds or as mixtures of different monoalkanols of the aforedescribed general formula.

The amount of mono-alkanol compound employed will vary depending on such factors as the nature of the particular fuel, the conditions under which it is handled, the type of metal surface involved, etc. For example, from about 0.05 to about 5 wt. percent, preferably from about 75 end point gas oil and 25% of a light Coker oil, after 2 to about 4 carbon atoms; and n represents an integer of 1 and 2.

2. The composition of claim 1 wherein the liquid hydrodesulfurized hydrocarbon fuel possesses an initial boiling point of about 400 F.

3. The composition of claim 1 wherein the liquid bydrodesulfurized hydrocarbon fuel is a distillate fuel oil.

4. The composition of claim 1 wherein said monoalkanol is isopropylaminoethanol.

5. The composition of claim 1 wherein said monoalkanol is ethylaminoethanol.

6. The composition of claim 1 wherein said monoalkanol is butylaminoethanol.

7. The composition of claim 1 Which contains water 2,643,178 6/1953 Waehter et a1. 21-25 in an amount sufficient to promote vapor phase corrosion. 2,706,677 4/ 1955 Duncan et a1. 4471 8. The composition of claim 1 wherein said mono- 2,775,533 12/1956 Healy 212.7 aikanol compound is present in an amount from about 2,889,276 6/1959 Barrett et a1. 212.5 0.05 to about 5 wt. percent. 5

9. The composition of claim 1 wherein the said mono- OTHER CES alkanol 1S methylamlnoethanol Plavsic: Chemical Abstracts, vol. 50 (1956), pages 9268 and 9269. References Cited UNITED STATES PATENTS 1O DANIEL E. WYMAN, Primary Examiner.

2,497,553 2/1950 Long 260--584 W. H. CANNON, Assistant Examiner.

2,512,949 6/1950 Lieber 212.5

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,372,009 March 5, 1968 Hans F. Waldmann It is certified that errer appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, lines 63 and 64, for "integer of 1 and 2" read integer of 1 to 2 Signed and sealed this 1st day of July 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

1. A LIQUID HYDRODESULFURIZED HYDROCARBON FUEL COMPOSITION NORMALLY TENDING TO PROMOTE VAPOR PHASE CORROSION, CONTAINING A LIQUID HYDRODESULFURIZED HYDROCARBON FUEL HEAVIER THAN GASOLINE AND AN EFFECTIVE AMOUNT OF AN ALKYL AMINO MONO-ALKANOL COMPOUND OF THE FORMULA: 